Perhaps old news to some, seeing that it's from a 1991 article. Too bad they didn't bring along an electrical engineer or two to provide some circuit analysis.
March 30, 1991 Issue of New Scientist, pg 10 wrote:
Underground current electrifies Australia
30 March 1991
Underground current in Australia
The world's longest natural electric current has been discovered under Australia. The current passes through sedimentary rocks for more than 6000 kilometres across the Australian outback. Its nearest rival, some 2000 kilometres shorter, is a current running from Wyoming into Canada in North America.
Francois Chamalaun from Flinders University, who discovered the current, says that similar currents may exist under other continents. They could have been formed as the land masses collided hundreds of millions of years ago. According to Chamalaun, the current is induced by the Earth's ever-changing magnetic field.
In the most extensive geomagnetic survey carried out in Australia, the Bureau of Mineral Resources placed an array of 54 highly sensitive magnetometers in a grid across Australia. The instruments detected a weak electrical current between 15 and 45 kilometres below the surface. The width of the current varies between 50 and 200 kilometres.
The current runs from the continental shelf off Broome in the far northwest of Western Australia, down into the north of South Australia, and then up through Queensland into the Gulf of Carpentaria. A side branch of the main current runs from near Birdsville in South Australia, through the Flinders Ranges, and into Spencer Gulf near Adelaide.
The current runs along fracture zones in sedimentary basins. The fracture zones, which formed as ancient plates of the Earth's crust collided, contain alkaline fluids which conduct electricity well. The current is extremely weak. It would not provide enough power to light a lamp. But if the current was involved with the formation of the ancient sedimentary basins, as scientists believe, it may provide clues to deposits of oil and gas. It may also help to explain the geological origins of the Australian continent.
From issue 1762 of New Scientist magazine, 30 March 1991, page Page10
http://www.newscientist.com/article/mg1 ... alia-.html